1. Field of the Invention
This invention relates to an apparatus for measuring bearing wear in multiple orientations. More particularly, the present invention relates to an apparatus that can measure the bearing wear in a rotor pitch link in axial, longitudinal, and transverse directions.
2. Description of the Background Art
As is known in the art, pitch links are adapted to be secured between the rotor blade and the rotor hub of a rotary wing aircraft. Pitch links rotate along with the rotor hub and permit the individual blades to be pitched so they can generate upward and forward thrusts. Pitch links are subjected to enormous cyclic stresses during the course of a typical flight. For this reason, pitch links must be constantly monitored for any signs of fatigue or damage. The failure to properly inspect pitch links for damage can have dire consequences, as even the smallest structural defect can lead to catastrophic results.
Various rotor pitch link designs have been advanced over the years that promote safety and/or adjustability. An example of one such design is described in U.S. Pat. No. 3,786,695 to Barrett. Barrett discloses a redundant pitch link, wherein a primary load path is provided for use during normal operation and a secondary load path is provided in the event the primary load path becomes inoperable. Accordingly, one load path remains operable in the event the first load path suffers a structural failure. The link of Barrett is also adjustable.
An adjustable pitch link is also described in U.S. Pat. No. 5,946,981 to Ide et al. Ide discloses a pitch link with first and second shaft members that are threadingly engaged with one another. The link further includes spherical bearings that are mounted in the rod ends. A guide member is also provided for guiding the first shaft member in an axial direction. Pitch link can also be adjusted automatically to reduce vibrations.
Thus, although the background art discloses pitch link constructions with improved structural integrity and adjustability, none of the background art is aimed at improved measuring techniques for detecting wear within a rotor pitch link and its associated bearings. The present invention is directed at fulfilling this need.